docs: def search(self,search_text=None,response_type=None,params=None):
          """
          Function to request economic data series that match search text.
          `<https://research.stlouisfed.org/docs/api/fred/series_search.html>`_
  
          :arg str search_text: The words to match against economic data series. Required.
          :arg str response_type: File extension of response. Options are 'xml', 'json',
                          'dict','df','numpy','csv','tab,'pipe'. Required.
          :arg str search_type: Determines the type of search to perform. Options are 'full_text','series_id'
          :arg str realtime_start: The start of the real-time period. Format "YYYY-MM-DD"
          :arg str realtime_end: The end of the real-time period. Format "YYYY-MM-DD"
          :arg int limit: The maximum number of results to return. Options 1 to 1000
          :arg int offset: Data offset. Options >=0
          :arg str order_by: Order results by values of the specified attribute. Options are 'search_rank',
                              'series_id', 'title', 'units', 'frequency', 'seasonal_adjustment', 'realtime_start',
                              'realtime_end', 'last_updated', 'observation_start', 'observation_end', 'popularity'
          :arg str sort_order: Sort results for attribute values specified by order_by. Options are 'asc','desc'
          :arg str filter_variable: The attribute to filter results by. Options are  'frequency', 'units','seasonal_adjustment'
          :arg str filter_value: The value of the filter_variable attribute to filter results by.
          :arg str tag_names: Tag names used to match series. Separate with semicolon as in "income;bea"
          :arg str exclude_tag_names: Tag names used to exclude series. Separate with semicolon as in "income;bea"
          :arg bool ssl_verify: To verify HTTPs.
          """
          path = '/series/search?'
          params['search_text'] = search_text
          response_type = response_type if response_type else self.response_type
          if response_type != 'xml': params['file_type'] = 'json'
          response = _get_request(self.url_root,self.api_key,path,response_type,params,self.ssl_verify)
          return response